The present invention relates to a catalyst useful for directly and efficiently nitrating and/or carboxylating a substrate by using at least one reactant selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen, and a compound obtained by using the catalyst and a process for producing the compound (a nitration/carboxylation process, a process for producing a compound having a nitro group and/or carboxyl group, a novel adamantane derivative, and a process for producing an adamantane derivative) using the catalyst.
Nitro compounds are commonly utilized as a raw material for medicine, agricultural chemicals, dyes, solvents and explosives, a raw material for amino compounds, and the like. Moreover, carboxylic acids (carboxy compounds) are useful as a raw material of a variety of compounds such as esters. Among them, dicarboxylic acids are useful as a raw material of polyesters.
Nitration of hydrocarbons is generally conducted by a nitric acid process which employs a mixed acid (a mixture of nitric acid and sulfuric acid). However, the nitric acid process requires a strong acid with high concentration in a large amount. Besides, since the nitration reaction is exothermic, it is difficult to improve its reaction operability. Furthermore, in the nitric acid process, large amounts of nitrogen oxides produce, which cause environmental pollution and thus have to be treated in a proper manner.
As a nitration process, use of N2O5 and ozone in the presence of an iron catalyst has been suggested for nitration of aromatic compounds (e.g., toluene) or alicyclic compounds (e.g., adamantane). Due to the use of NO3 as a reactant, this nitration process can proceed smoothly at a lower temperature. However, a catalyst should be incorporated in order to increase the reaction rate, and additional equipment such as an ozone-generating apparatus should be installed for the generation of ozone.
Carboxyl compounds (e.g., phthalic acid) can be obtained by, for example, an oxidation of a substrate (e.g., naphthalene). In Such oxidation reaction, a carboxyl compound having carbon atoms fewer than a substrate can be usually obtained. Moreover, in order to obtain a carboxyl compound of a bridged cyclic hydrocarbon (e.g., 1-carboxyladamantane) by an oxidation reaction, it is required that a group which can be converted to a carboxyl group by oxidation (e.g., methylol group) is introduced to a methine carbon atom, and then the methine carbon atom is oxidized. It is considerably difficult.
As a carboxylation process of a hydrocarbon compound, for example, a process for providing a carboxylic acid by using Grignard reaction is broadly known. In this process, many reaction steps are required since a substrate can not be directly carboxylated and include that a special compound such as an organic metal compound (e.g., a Grignard compound) is previously prepared from a substrate, carbon dioxide is allowed to act on the organic metal compound, and the organic metal compound is hydrolyzed to be carboxylated. Further, it is difficult to prepare the organic metal compound, additionally the compound is not convenient to handle.
Japanese Patent Application Laid-open No.38909/1996 (JP-A-8-38909) discloses a process which comprises contacting a substrate with oxygen to oxidize in the presence of an imide compound such as N-hydroxyphthalimide to provide a corresponding oxide (e.g., a carboxylic acid). In this process, a process for producing adipic acid from cyclohexane is described. In this process, a carboxyl compound having the same number of carbon atoms as a substrate can be obtained usually.
On the other hand, adamantane has a three-dimensionally symmetric structure and skeletons which insure mutual stabilization of each ring, and as a result, endowed with distinctive functions. Various highly functionalized copolymers can be obtained, for example, by introducing a functional group such as a carboxyl group or an amino group to adamantane and optionally deriving to other derivatives thereof. There have been proposed various production processes for obtaining such copolymers from a functional group-introduced adamantane derivative. The processes include, for example, a process of producing a polyester [e.g., Japanese Patent Application Laid-open No. 21090/1975 (JP-A-50-21090)], a process of producing a polycarbonate [e.g., U.S. Pat. No. 3,594,427], a process for producing a polyamide or a polyimide [e.g., U.S. Pat. No. 3,832,332], a process for producing a polyurethane [e.g., Japanese Patent Publication No. 12891/1969 (JP-B-44-12891)], a process for producing a polysulfone and a polysulfonate [e.g., U.S. Pat. No. 3,753,950], and a process for producing a vinyl polymer [e.g., Japanese Patent Publication No. 28419/1971 (JP-B-46-28419)].
These polymers provided from an adamantane derivative have generally excellent functions or characteristics (high functionality). They have, for example, optical characteristics such as small light-inducing loss, high refractive index, double refraction index, excellent characteristics such as moisture resistance, excellent heat resistance (heat resisting property) and thermal expansivity. Such excellent characteristics cannot be achieved with the use of conventional polymers. Accordingly, applications of said polymer have been investigated for optical materials such as optical fibers, optical elements, optical lenses, hologram, optical discs, and contact lenses, transparent resin coating compositions for organic glasses, electric conductive polymers, photosensitive materials, fluorescent materials and so forth.
On the other hand, an amino derivative derived from an alcohol of an adamantane is useful for introducing various pharmaceuticals and/or agricultural chemicals each having excellent pharmacological activity, and is used as a therapeutic agent for Parkinson""s disease such as xe2x80x9cSYMMETRELxe2x80x9d (a trade name). A diamino body of adamantane is useful as an intermediate material for antibacterial drugs (agents) or antiviral drugs (agents).
The above mentioned diamino body (diamino form) of the adamantane is produced by aminating a dihalo body obtained by halogenating a diol body of an adamantane. However, in a process for the formation of a salt of the diamino body obtained by aminating the dihalo body of adamantane, a side reaction tends to occur, additionally it is difficult to separate and collect a free diamino body in a high yield.
It is, therefore, an object of the present invention to provide a catalyst which can efficiently nitrate and/or carboxylate a substrate, and a nitration and/or carboxylation process using the catalyst.
It is another object of the present invention to provide a catalyst which can nitrate or carboxylate a substrate by using at least one reactant selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen even in a mild or moderate condition, and a nitration and/or carboxylation process of a substrate using the catalyst.
A further object of the present invention is to provide a catalyst which can provide a compound having at least one functional group selected from nitro group and carboxyl group with high conversion and selectivity, and a process for producing the compound having a functional group by using the catalyst.
Another object of the present invention is to provide a process for nitration which can utilize effectively nitrogen oxides, which cause environmental pollution, for providing nitro compounds with high conversion and selectivity.
Further object of the present invention is to provide a process for producing a carboxyl compound which has more carbon atoms than the number of carbon atoms of a substrate, efficiently with simple operation at fewer steps.
Still further object of the present invention is to provide a novel adamantane derivative.
Still another object of the present invention is to provide a process which can produce a diamino body of adamantane in high yield.
The inventors of the present invention did intensive investigation to accomplish the above objects, and finally found that a reaction of at least one reactant selected from (i) a nitrogen oxide (e.g., N2O3, N2O) and (ii) a mixture of carbon monoxide and oxygen with a substrate in the presence of a catalyst comprising a specific imide compound, efficiently introduce at least one functional group selected from a nitro group and a carboxyl group to the substrate and that useful adamantane derivatives including a novel adamantane derivative can be produced by using the above method.
Thus, a catalyst of the present invention is for introducing at least one functional group selected from a nitro group or a carboxyl group to a substrate by contacting the substrate with at least one reactant selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen to and comprises an imide compound shown by the following formula (1): 
wherein R1 and R2 may be the same or different from each other, and represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, and an acyl group, and R1 and R2 may bond together to form a double bond, or an aromatic or non-aromatic ring; Y represents an oxygen atom or a hydroxyl group; and n denotes an integer of 1 to 3.
The catalyst may comprise the imide compound shown by the formula (1) and a co-catalyst. As the co-catalyst, there may be employed, for example, a compound containing at least one element selected from the group consisting of Group 2A elements of the Periodic Table of Elements, transition metal elements and Group 3B elements of the Periodic Table of Elements.
According to the process of the present invention, in the presence of the imide compound shown by the formula (1), or the imide compound and the co-catalyst, a substrate is allowed to contact with at least one reactant selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen to introduce at least one functional group selected from a nitro group and a carboxyl group to the substrate. The substrate includes, for example, (a) a compound having a methyl group or a methylene group at an adjacent site of an unsaturated bond, (b) a homo- or hetero cyclic compound having a methylene group, (c) a compound having a methine carbon atom, (d) a compound having a methyl group or a methylene group at an adjacent site of an aromatic ring and (e). a compound having a methylene group at an adjacent site of a carbonyl group. As the nitrogen oxide, there may be employed, for example, a compound shown by the formula:
NxOy
wherein x denotes an integer of 1 or 2 and y denotes an integer of 1 to 6;
such as N2O3, NO2.
The present invention comprises a process for producing a compound having at least one functional group selected from a nitro group and a carboxyl group by using the above process, as well.
A novel adamantane derivative of the present invention is a compound shown by the following formula (2) or (3): 
wherein X1 represents a nitro group, an amino group or N-substituted amino group which may be protected by a protective group, a carboxyl group which may be protected by a protective group, or a hydroxymethyl group which may be protected by a protective group; and X3 and X4 may be the same or different from each other, and represents a hydrogen atom, an alkyl group, a nitro group, an amino group or N-substituted amino group which may be protected by a protective group, a carboxyl group which may be protected by a protective group, a hydroxymethyl group which may be protected by a protective group or an isocyanato group;
(i) when X1 is a nitro group, X2 represents an amino group or N-amino group which may be protected by a protective group, a hydroxymethyl group which may be protected by a protective group, or an isocyanato group;
(ii) when X1 is an amino group or N-substituted amino group which may be protected by a protective group, X2 represents an isocyanato group;
(iii) when X1 is a carboxyl group which may be protected by a protective group, X represents a hydroxymethyl group which may be protected by a protective group, or an isocyanato group; and
(iv) when X1 is a hydroxymethyl group which may be protected by a protective group, X represents an isocyanato group; 
wherein X5 represents a carbamoyl group which may have a substituent, a nitro group, a substituted hydoroxycarbonylamino group, or a saturated aliphatic acylamino group or an aromatic acylamino group; X7 and X8 are the same or different from each other, and represent a hydrogen atom, an alkyl group, a nitro group, an amino or N-substituted amino group which may be protected by a protective group, a carboxyl group which may be protected by a protective group, a hydroxymethyl group which may be protected by a protective group, or an isocyanato group;
(i) when X5 is a carbamoyl group which may have a substituent, X6 represents a carboxyl group, a substituted hydroxycarbonyl group, an amino group or N-substituted amino group which may be protected by a protective group, or a nitro group;
(ii) when X5 is a nitro group, X6 represents a substituted hydroxycarbonyl group;
(iii) when X5 is a substituted hydroxycarbonylamino group, X6 represents a substituted hydroxycarbonyl group, a hydroxymethyl group which may be protected by a protective group, or an amino group which may be protected by a protective group; and
(iv) X5 is a saturated aliphatic acylamino group or an aromatic acylamino group, X6 represents a carboxyl group, a hydroxymethyl group which may be protected by a protective group, or an amino group which may be substituted by an alkyl group;
or a salt thereof.
The present invention provides a process for producing a diaminoadamantane derivative shown by the following formula (2j): 
wherein X1j and X2j represent an amino group or N-substituted amino group which may be protected by a protective group; and X3 and X4 have the same meanings as defined above;
which comprises steps of
contacting a compound shown by the following formula (2h): 
wherein X2h represents a hydrogen atom or a nitro group; X3 and X4 are have the same meanings as defined above; with a nitrogen oxide in the presence of the imide compound shown by the formula (1), to produce a dinitroadamantane derivative shown by the following formula (2i): 
wherein X1i and X2i each represents a nitro group; and X3 and X4 have the same meanings as defined above; and
reducing said dinitroadamantane derivative shown by the formula (2i) to produce a corresponding diamino compound.
In the compound shown by the formula (1), the halogenatom, as the substituents R1 and R2, includes iodine, bromine, chlorine and fluorine atoms. The alkyl group includes, for example, a straight chain or branched chain alkyl group having about 1 to 10 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, and decyl group. An illustrative preferred alkyl group includes alkyl groups having about 1 to 6 carbon atoms, in particular lower alkyl groups having about 1 to 4 carbon atoms.
As the aryl group, there may be mentioned, for instance, a phenyl group and a naphthyl group. Examples of the cycloalkyl group include cyclopentyl, cyclohexyl, and cyclooctyl groups. The alkoxy group includes, for example, an alkoxy group having about 1 to 10 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, pentyloxy, andhexyloxy group. Among them, alkoxy groups having about 1 to 6 carbon atoms, in particular lower alkoxy groups having about 1 to 4 carbon atoms are preferable.
Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having about 1 to 10 carbon atoms in the alkoxy moiety such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, t-butoxycarbonyl, pentyloxycarbonyl, and hexyloxycarbonyl group. A preferred alkoxycarbonyl group includes those each having about 1 to 6 carbon atoms in the alkoxy moiety, in particular lower alkoxycarbonyl groups each having about 1 to 4 carbon atoms in the alkoxy moiety.
The acyl group includes, for instance, an acyl group having about 1 to 6 carbon atoms such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, and pivaloyl group.
The substituents R1 and R2 may be either the same or different from each other. In the formula (1), R1 and R2 may bond together to form a double bond, or an aromatic or non-aromatic ring. A preferred aromatic or non-aromatic ring may be a ring having about 5 to 12 members, in particular about 6 to 10 members. Such a ring may be a heterocyclic ring or a condensed heterocyclic ring, and it may practically be a hydrocarbon ring. As such a ring, there may be mentioned, for instance, non-aromatic alicyclic rings (e.g., cycloalkane rings which may have a substituent, such as cyclohexane ring, and a cycloalkene rings which may have a substituent, such as a cyclohexene ring), non-aromatic bridged (cross-linked) rings (e.g., bridged hydrocarbon rings which may have a substituent, such as a 5-norbornene ring), aromatic rings which may have a substituent, such as a benzene ring, a naphthalene ring. The ring may practically comprise an aromatic ring.
A preferred imide compound includes compounds shown by the following formula: 
where R3, R4 and R6 independently represent a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, a cyano group, an amino group or a halogen atom; and R1, R2, Y and n have the same meanings as defined above.
In the substituents R3, R4, R5 and R6, the alkyl group includes alkyl groups similar to those exemplified above, in particular alkyl groups each having about 1 to 6 carbon atoms. The alkoxy group includes the same alkoxy groups as mentioned above, in particular lower alkoxy groups each having about 1 to 4 carbon atoms. Examples of the alkoxycarbonyl group include the same alkoxycarbonyl groups as exemplified above, in especial lower alkoxycarbonyl groups each having about 1 to 4 carbon atoms in the alkoxy moiety. As the acyl group, there may be mentioned the similar acyl groups to those mentioned above, in particular acyl groups each having about 1 to 6 carbon atoms. Examples of the halogen atom include fluorine, chlorine and bromine atoms. The substituents R3, R4, R5 and R6 may practically be hydrogen atoms, lower alkyl groups each having 1 to 4 carbon atoms, carboxyl groups, nitro groups or halogen atoms, respectively.
The symbol Y in the formula (1) denotes an oxygen atom or a hydroxyl group, and n usually denotes about 1 to 3, preferably 1 or 2. The compound shown by the formula (1) can be used singly or in combination of two or more in the nitration reaction.
As examples of the acid anhydride corresponding to the imide compound of the formula (1), there may be mentioned a saturated or unsaturated aliphatic dicarboxylic acid anhydride such as succinic anhydride, maleic anhydride; a saturated or unsaturated nonaromatic cyclic polycarboxylic acid anhydride (an alicyclic polycarboxylic acid anhydride) such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride (1,2-cyclohexanedicarboxylic acid anhydride), 1,2,3,4-cyclohexanetetracarboxylic acid 1,2-anhydride; a bridged cyclic polycarboxylic acid anhydride (an alicyclic polycarboxylic acid anhydride) such as hetic anhydride, himic anhydride; an aromatic polycarboxylic acid anhydride such as phthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, nitrophthalic anhydride, trimellitic anhydride, methylcyclohexenetricarboxylic anhydride, pyromellitic anhydride, mellitic anhydride, 1,8;4,5-naphthalenetetracarboxylic acid dianhydride.
Examples of a preferred imide compound include N-hydroxysuccinimide, N-hydroxymaleimide, N-hydroxyhexahydrophthalimide, N,Nxe2x80x2-dihydroxycyclohexanetetracarboximide, N-hydroxyphthalimide, N-hydroxytetrabromophthalimide, N-hydroxytetrachlorophthalimide, N-hydroxyhetimide, N-hydroxyhimimide, N-hydroxytrimellitimide, N,Nxe2x80x2-dihydroxypyromellitimide, N,N-dihydroxynaphthalene-tetracarboximide and so forth. A typically preferable imide compound includes an N-hydroxyimide compound derived from an alicyclic polycarboxylic acid anhydride, in particular from an aromatic polycarboxylic acid anhydride, such as N-hydroxyphthalimide.
The imide compound may be prepared by a conventional imidation process (a process for the formation of an imide), such as a process that comprises the steps of allowing a corresponding acid anhydride to react with hydroxylamine NH2OH for ring-opening. of an acid anhydride group, and closing the ring to form the imide.
A catalyst may comprise the imide compounds of the formula (1) and a co-catalyst. The co-catalyst includes or comprises metal compounds such as a compound comprising or containing a Group 2A element of the Periodic Table of Elements (e.g., magnesium, calcium, strontium, barium), a transition metal compound, or compounds containing a Group 3B element (e.g., boron B, aluminium Al) of the Periodic Table of Elements. These co-catalysts may be employed independently or in combination of two or more.
As the elements of the transition metal, there may be mentioned, for instance, Group 3A elements of the Periodic Table of Elements (e.g., scandium Sc, yttrium Y, and a lanthanoid element such as lanthanum La, cerium Ce, samarium Sm, an actinoid element such as actinium Ac), Group 4A elements of the Periodic Table of Elements (e.g., titanium Ti, zirconium Zr, hafnium Hf), Group 5A elements (e.g., vanadium V, niobium Nb, tantalum Ta), Group 6A elements (e.g., chromium Cr, molybdenum Mo, tungsten W), Group 7A elements (e.g., manganese Mn, technetium Tc, rhenium Re), Group 8 elements (e.g., iron Fe, ruthenium Ru, osmium Os, cobalt Co, rhodium Rh, iridium Ir, nickel Ni, palladium Pd, platinum Pt), Group 1B elements (e.g., copper Cu, silver Ag, gold Au) and Group 2B elements (e.g., zinc Zn, cadmium Cd) of the Periodic Table of Elements.
A preferred element constituting the co-catalyst includes elements of the transition metals, for example, Group 3A elements of the Periodic Table of Elements such as lanthanoid elements (e.g., Ce), actinoid elements; Group 4A elements such as Ti, Zr; Group 5A elements such as V, Nb; Group 6A elements such as Cr, Mo, W; Group 7A elements such as Mn, Tc, Re; Group 8 elements such as Fe, Ru, Co, Rh, Ni; or Group 1B elements such as Cu) and Group 3B elements such as B. The oxidation number of the metal elements constituting the co-catalyst is not particularly limited, and may be, for example 0, +2, +3, +4, +5 and +6 according to the variety of elements. The divalent transition metal compounds (such as a divalent cobalt compound, a divalent manganese compound) may be practically used as the co-catalyst.
The co-catalyst may be a simple substance or hydroxide of a metal. The co-catalyst may practically be an a metal oxide (comprising a double oxide or an oxygen acid or a salt thereof) comprising the element, an organic acid salt comprising the element, an inorganic acid salt comprising the element, a halide comprising the element, a coordinate compound (a complex) comprising the metal element, or a polyacid (a heteropolyacid or an isopolyacid) comprising the element or a salt thereof.
As the boron compound, there may be mentioned, for example, a boron hydride (e.g., borane, diborane, tetraborane, pentaborane, decaborane); aboric acid (e.g., orthoboric acid, metaboric acid, tetraboric acid); a borate (e.g., a nickel borate, magnesium borate, manganese borate); boron oxides such as B2O3; nitrogen-containing boron compounds such as borazane, borazene, borazine, boron amide, boron imide; halides such as BF3, BCl3, tetrafluoroborate; esters of boric acid (e.g., methyl borate, phenyl borate). A preferred boron compound includes boron hydrides and boric acids such as orthoboric acid or salts thereof, in particular a boric acid.
The hydroxide includes Mn(OH)2, MnO(OH), Fe(OH)2 and Fe(OH)3, typically speaking. Examples of the metallic oxide include Sm2O3, TiO2, ZrO2, V2O3, V2O5, CrO, Cr2O3, MoO3MnO, Mn3O4, Mn2O3, Mno2, Mn2O7, FeO, Fe2O3, Fe3O4, RuO2, RuO4, CoO, CoO2, Co2O3, RhO2, Rh2O3, Cu2O3. As examples of the double oxide or oxygen acid salt, there may be mentioned MnAl2O4, MnTiO3, LaMnO3, K2Mn2O5, CaO.xMnO2 (x=0.5, 1, 2, 3, 5), manganese salts [e.g., manganates (V) such as Na3MnO4, Ba3(MnO4)2; manganates(VI) such as K2MnO4, Na2MnO4, BaMnO4; permanganates such as KMnO4, NaMnO4, LinO4, NH4MnO4, CsMnO4, AgMnO4, Ca(MnO4)2, Zn(Mno4)2, Ba(MnO4)2, Mg(MnO4)3, Cd(MnO4)2].
As the organic acid salts, there may be exemplified as salts of a C2-20 fatty acid such as cobalt acetate, manganese acetate, cobalt propionate, manganese propionate, cobalt naphthenate, manganese naphthenate, cobalt stearate and manganese stearate, and manganese thiocyanate and corresponding salts of Ce, Ti, Zr, V, Cr, Mo, Fe, Ru, Ni, Pd, Cu and Zn. The inorganic acid salt includes, for instance, nitrates such as cobalt nitrate, iron nitrate, manganese nitrate, nickel nitrate and copper nitrate, and sulfates, phosphates and carbonates each corresponding to these nitrates (e.g., cobalt sulfate, iron sulfate, manganese sulfate, cobalt phosphate, iron phosphate, manganese phosphate, an iron carbonate, a manganese carbonate, iron perchlorate). As the halides, there may be mentioned, for instance, chlorides such as SmCl3, SmCl2, TiCl2, ZrCl2 ZrOCl2, VCl3, VOCl2, MnCl2, MnCl3, FeCl2, FeCl3, RuCl3, CoCl3, RhCl2, RhCl3, NiCl2, PdCl2, PtCl2, CuCl and CuCl2, or halides such as fluorides, bromides or iodides each corresponding to these chlorides (e.g., MnF2, MnBr2, MnF3, FeF2, FeF3, FeBr2, FeBr3, FeI2CuBr, CuBr2), complex halides such as M1MnCl3, M12MnCl4, M12MnCl5, M12MnCl6, wherein M1 represents a monovalent metal.
The ligand constituting the complex includes, for example, OH (hydroxo); alkoxy groups such as methoxy, ethoxy, propoxy and butoxy group; acyl groups such as acetyl (OAc), propionyl group; alkoxycarbonyl groups such as methoxycarbonyl (acetato), ethoxycarbonyl group; acetylacetonato (AA), cyclopentadienyl group; halogen atoms such as chlorine, bromine; CO, CN, oxygen atom, H2O (aquo); phosphorus compounds such as a phosphine (e.g., triphenylphosphine and other triarylphosphine); nitrogen-containing compounds such as NH3 (ammine), NO, NO2 (nitro), NO3 (nitrato), ethylenediamine, diethylenetriamine, pyridine and phenanthroline. In the complexes or complex salts, the same or different ligands may be coordinated singly or in combination of two or more. The preferable ligand includes, for example, OH, an alkoxy group, an acyl group, an alkoxycarbonyl group, acetylacetonato, a halogen atom, CO, CN, H2O (aquo), triphenylphosphine and other phosphorus compounds, and a nitrogen-containing compound inclusive of NH3, NO2and NO3.
A preferable complex includes the complexes containing the preferable transition metal element. The transition metal element and the ligand may optionally be employed in combination to form a complex. Such a complex includes, for instance, acetylacetonato complexes [e.g., acetylacetonato complex of Ce, Sm, Ti, Zr, V, Cr, Mo, Mn, Fe, Ru, Co, Ni, Cu and Zn, titanylacetylacetonato complex TiO(AA)2, zirconylacetylacetonato complex ZrO(AA)2, vanadylacetylacetonato complex VO(AA)2], cyano complexes [e.g., a hexacyanomanganate(I), a hexacyanoferrate(II)], carbonyl complexes or cyclopentadienyl complexes [e.g., tricarbonylcyclopentadienylmanganese(I), biscyclopentadienylmanganese(II), biscyclopentadienyliron(II), Fe(CO)5, Fe2(CO)9, Fe3(CO)12], nitrosyl compounds [e.g., Fe(NO)4, Fe(CO)2(NO)2], thiocyanato complexes [e.g., thiocyanatocobalt, thiocyanatomanganese, thiocyanatoiron], or acetyl complexes [e.g. cobalt acetate, manganese acetate, iron acetate, copper acetate, zirconyl acetate ZrO(OAc)2, titanyl acetate TiO(OAc)2, vanadyl acetate VO(OAc)2].
The polyacid is practically at least one member selected from Group 5 elements or Group 6 elements of the Periodic Table of Elements, such as V (vanadic acid), Mo (molybdic acid) and W (tungstic acid), typically speaking. There is no particular limit as to the central atom, and it may be any of, for instance, Be, B, Al, Si, Ge, Sn, Ti, Zr, Th, N, P, As, Sb, V, Nb, Ta, Cr, Mo, W, S, Se, Te, Mn, I, Fe, Co, Ni, Rh, Os, Ir, Pt or Cu. As illustrative examples of the heteropolyacid, there may be mentioned cobaltmolybdic acid, cobalttungstic acid, molybdenumtungstic acid, manganesemolybdic acid, manganesetungstic acid, manganesemolybdenumtungstic acid, vanadomolybdophosphoric acid, manganesevanadiummolybdic acid, manganesevanadomolybdophosphoric acid, vanadiummolybdic acid, vanadiumtungstic acid, silicomo-lybdic acid, silicotungstic acid, phosphomolybdic acid, phosphotangstic acid, phosphovanadomolybdic acid, and phosphovanadotangstic acid.
The catalysts have high activities. A combination of the catalyst with at least one reactant selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen, accelerates a nitration and/or carboxylation reaction of a substrate even in a mild or moderate condition.
A catalyst comprising the imide compound shown by the formula (1) or the imide compound and the above co-catalyst may be whichever of a homogeneous system or a heterogeneous system. The catalyst may be a solid catalyst comprising a catalytic component supported on a support or carrier, as well. As the support, use can be practically made of porous supports such as active carbon, zeolite, silica, silica-alumina, and bentonite. In the solid catalyst, the supporting amount of the imide compound of the formula (1) as the catalyst component may be about 0.1 to 50 parts by weight, preferably about 0.5 to 30 parts by weight and more preferably about 1 to 20 parts by weight relative to 100 parts by weight of the support. The supporting amount more of the co-catalyst is about 0.1 to 30 parts by weight, preferably about 0.5 to 25 parts by weight, and more preferably about 1 to 20 parts by weight, relative to 100 parts by weight of the support.
The nitrogen oxide may be shown by the formula:
NxOy
wherein x denotes an integer of 1 or 2 and y denotes an integer of 1 to 6.
In the compound shown by the above formula, when x is 1, y is usually an integer of 1 to 3; and when x is 2, y is usually an integer of 1 to 6.
Such nitrogen oxide may be exemplified N2O, NO, N2O3, NO2, N2O4, N2O5, NO3 and N2O6. These nitrogen oxides may be used independently or in combination.
The preferred nitrogen oxide includes (i) a nitrogen oxide (particularly N2O3) generated by the reaction of at least one nitrogen oxide selected from dinitrogen oxide (N2O) and nitrogen monoxide (NO) with oxygen, or a nitrogen oxide containing N2O3 as a main component and (ii) a nitrogen dioxide (NO2) or a nitrogen oxide containing NO2 as a main component.
Nitrogen oxide N2O3 may be easily obtained by a reaction of N2O and/or NO with oxygen. To be more concrete, the nitrogen oxide may be prepared by introducing nitrogen monoxide and oxygen to a reactor to produce a blue liquid N2O3. Therefore, the nitration reaction may be carried out by introducing N2O and/or NO and oxygen to a reaction system without producing N2O3 in advance.
Incidentally, a pure oxygen may be used or may be distilled by an inert gas (e.g., carbon dioxide, nitrogen, helium and argon). Air may be used as an oxygen source.
Carbon monoxide or oxygen employed in the present invention may be pure one, and may be diluted with a inert gas (e.g., nitrogen, helium, argon, carbon dioxide). The oxygen source may be air. To the reaction system, a mixture previously mixed carbon monoxide with oxygen may be introduced, and carbon monoxide and oxygen may separately introduced.
In the present invention, as a reactant, there may be employed, for example, (i) the nitrogen oxide, (ii) the mixture of carbon monoxide and oxygen, or a combination of (i) the nitrogen oxide and (ii) the mixture of carbon monoxide and oxygen. In the case of using (i) the nitrogen oxide as a reactant, a substrate is nitrated to generate a nitro compound. In the case of using (ii) the mixture of the nitrogen monoxide and oxygen as the reactant, a substrate is carboxylated to generate a carboxyl compound. In the case of using (i) the nitrogen monoxide and (ii) the mixture of carbon monoxide and oxygen in combination as the reactant, a nitro compound and a carboxyl compound can be co-produced. In this case, use of a compound having plural reactive sites as a substrate can provide a compound which has a nitro group and a carboxyl group in the same molecule in one step by selecting a reaction condition (e.g., the ratio of the reactant (i) to (ii), a reaction temperature).
Species of substrates is not particularly restricted, and may be employed broad range of a saturated or unsaturated compound such as a hydrocarbon (e.g., an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon), a heterocyclic compound, an alcohol, an ether, a ketone, an aldehyde, a carboxylic acid or derivative thereof, and the like may be employed.
Preferred substrate comprises, for example, (a) a compound having a methyl group or a methylene group at the adjacent site of an unsaturated bond, (b) a homo- or heterocyclic compound having a methylene group, (c) a compound having a methine carbon atom, (d) a compound having a methyl group or a methylene group at the adjacent site of an aromatic ring and (e) a compound having a methyl group or a methylene group at the adjacent site of a carbonyl group. In the compound (b), the methylene group constitutes a 5- or 6-membered ring, and the compound (b) is usually a non-aromatic homo- or heterocyclic compound.
(a) The compound having a methyl group or a methylene group at the adjacent site of an unsaturated bond comprises an organic compound having a double bond and/or a triple bond. Examples of such compounds include propylene, 1-butene, 2-butene, butadiene, 1-pentene, 2-pentene, isoprene, 2-methyl-2-butene, 1-hexene, 2-hexene, 1,5-hexadiene, 2,3-dimethyl-2-butene, 3-hexene, 1-heptene, 2-heptene, 1,6-heptadiene, 1-octene, 2-octene, 3-octene, 1,7-octadiene, 2,6-octadiene, 1-nonene, 2-nonene, decene, decadiene, dodecadiene, dodecatriene, undecene, undecadiene and undecatriene.
(b) Examples of the homocyclic compound (b1) having methylene group include a cycloalkane (e.g., a cycloalkane having about 3 to 30 carbon atoms such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, methylcyclohexane, cyclooctane, 1,2-dimethylcyclohexane, cyclononane, isopropylcyclohexane, methylcyclooctane, cyclodecane, cyclododecane, cyclotridecane, cyclotetradecane, cyclopentadecane, cyclohexadecane, cyclooctadecane, cyclononadecane), a cycloalkene (e.g., a cycloalkene having about 3 to 30 carbon atoms such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, 1-methyl-1-cyclohexene, cyclooctene, cyclononene, cyclodecene, cyclododecene, limonene, menthene, menthone), a cycloalkadiene (e.g., a cycloalkadiene having about 5 to 30 carbon atoms such as cyclopentadiene, cyclohexadiene, cycloheptadiene, cyclooctadiene, cyclodecadiene, cyclododecadiene), a cycloalkatriene (e.g., cyclooctatriene), cycloalkatetraene (e.g., cyclooctatetraene) and a condensed polycyclic hydrocarbon.
(b) The heterocyclic compound (b2) having a methylene group comprises a 5- or 6-membered cyclic compound having at least one hetero atom selected from nitrogen atom, oxygen atom and sulfur atom, or a condensed heterocyclic compound which is condensed by the 5- or 6-membered cyclic compound having the hetero atom at an aromatic ring, such as dihydrofuran, tetrahydrofuran, pyran, dihydropyran, tetrahydropyran, piperidine, piperadine, pyrrolidine, xanthene, and the like.
(c) The compound having a methine carbon atom (methylidine group) comprises, for instance, a chain hydrocarbon (c1) having a tertiary carbon atom, a bridged cyclic hydrocarbon (c2) and the like.
Examples of the chain hydrocarbon (c1) having a tertiary carbon atom include a aliphatic hydrocarbon having about 4 to 10 carbon atoms such as isobutane, isopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 2,4-dimethylpentane, 2,3,4-trimethylpentane, 3-ethylpentane, 2,3-dimethylhexane, 2,4-dimethylhexane, 3,4-dimethylhexane, 2,5-dimethylhexane, 2-propylhexane, 2-methylheptane, 4-methylheptane, 2-ethylheptane, 3-ethylheptane, 2,6-dimethylheptane, 2-methyloctane, 3-methyloctane, 2,7-dimethyloctane and 2-methylnonane.
The bridged cyclic hydrocarbon (c2) comprises, for example, a bridged cyclic hydrocarbon [e.g., bicyclo hydrocarbon such as decalin, hexahydroindan, carane, bornane, norbornene, norbornane, vinylnorbornene and norbornadiene; a tricyclo hydrocarbon such as homoblendane, adamantane and derivatives thereof (e.g., methyladamantane, 1,3-dimethyladamantane, ethyladamantane, chloroadamantane, adamantanol, adamantanone, methyladamantanone, dimethyladamantanone, formyladamantanone), tricyclo[4.3.1.12,5]undecane; and a tetracyclohydorocarbon such as tetracyclo[4.4.0.1.2,5.1. 7,10]dodecane], a dimer of a diene or hydrogen adduct thereof (e.g., dicyclopentane, dicyclohxane, dicyclopentene, dicyclohexadiene, dicyclopentadiene, tetrahydrodicyclopentadiene) and a terpene (e.g., pinane, pinene, camphor, bornene, caryophyllene).
The preferred compound (c) having a methine carbon atom includes a bridged cyclic hydrocarbon having about 6 to 16 carbon atoms, in particular about 7 to 14 (especially a bridged cyclic hydrocarbon such as adamantane or a derivative thereof).
(d) Examples of the compound having a methyl group or a methylene group at the adjacent site of an aromatic ring include an aromatic hydrocarbon having an alkyl group (e.g., toluene, o-, m- or p-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene (mesitylene), 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene (durene), 1,2,3,4,5,6-hexamethylbenzene, ethylbenzene, propylbenzene, cumene, o-, m- or p-ethyltoluene, butylbenzene, 1,4-diethylbenzene, 1-methylnaphthalene, 2-methylnaphthalene, 1,5-dimethylnaphthalene, 2,5-dimethylnaphthalene, 1-methylanthracene, 2-methylanthracene, 9-methylanthracene, dimethylanthracene, trimethylanthracene, 4,4xe2x80x2-dimethylbiphenyl, dibenzyl, diphenylmethane, triphenylmethane), an aromatic hydrocarbon having a cyclic methylene group (e.g., a condensed polycyclic aromatic hydrocarbon condesed by a about 5 to 8 -membered ring, such as indane, indene, tetralin, dihydronaohthalene, fluorene, phenalene) and a heterocyclic compound having an alkyl group (e.g., a picoline such as 2-methylfuran, 3-methylfuran, 2-methylpyran, 3-methylpyran, 4-methylpyran, 3,4-dimethylpyran, 4-methylchroman, 6-methylchroman, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine, a lutidine such as 2,3-dimethyipyridine, a collidine such as 2,4,6-trimethylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, methylquinoline and methylindole). The preferred compound (d) includes a compound having a methyl group or a methylene group at benzyl position.
(e) The compound having a (active) methyl group or methylene group at the adjacent site of a carbonyl group comprises, for instance, an aldehyde (e1), a ketone (e2) and a carboxylic acid or derivative thereof (e3).
The aldehyde (e1) comprises, for example, an aliphatic aldehyde (e.g., an aliphatic monoaldehyde having about 2 to 12 carbon atoms such as acetaldehyde, propionaldehyde, butylaldehyde, isobutylaldehyde, pentylaldehyde, hexylaldehyde, heptylaldehyde, octylaldehyde, nonylaldehyde and decylaldehyde, an aliphatic polyaldehyde such as malonaldehyde, succinaldehyde, adipic aldehyde and sebacic aldehyde), an aromatic aldehyde (e.g., benzaldehyde, anisaldehyde), an alicyclic aldehyde (e.g., formylcyclohexane, citronellal), a bridged cyclic aldehyde (e.g., formylnorbornene) and a heterocyclic aldehyde (e.g., nicotinic aldehyde, furfural).
Examples of the ketone (e2) include an aliphatic ketone (e.g., acetone, methylethylketone, methylisopropylketone, methylisobutylketone, methyl-t-butylketone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-octanone, 3-octanone, 4-octanone, 2-nonanone and 2-decanone), a cyclic ketone (e.g., a non-aromatic cyclic mono- or polyketone such as cyclopentanone, cyclohexanone, methylcyclohexanone, dimethylcyclohexanone, cycloheptanone, isophorone, cyclooctanone, cyclononanone, cyclodecanone, cyclohexadione and cyclooctadione; a cyclic ketone having an aromatic ring such as xcex1-tetralone, xcex2-tetralone and indanone), a bridged cyclic ketone (e.g., pinocamphone, pinocarbon), an aromatic ketone (e.g., acetophenene, propiophenone) and a heterocyclic ketone (e.g., pyrrolidone, pyperidone).
The carboxylic acid or derivatives thereof (e3) comprises, for. example, an aliphatic dicarboxylic acid or dericatives thereof (e.g., malonic acid or an ester thereof, succinic acid or an ester thereof and glutaric acid or an ester thereof).
These substrates may be substituted by a suitable functional group, such as a halogen atom, an oxo group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, an alkyl group, an alkenyl group (e.g., an allyl group), a cycloalkyl group, an aryl group, a vinyl group, an amino group, an alkylamino group, an amido group, a nitro group, a nitrile group, an acylamino group, a mercapto group, a sulfonyl group, a sulfinyl group, a sulfide group and a phosphino group.
In such substrates (a), (b), (c), (d) and (e), a nitro group or a carboxyl group can be introduced thereto at a carbon atom of a methyl or methylene group, or a methine carbon atom. To be specific, a nitro group or a carboxyl group can be smoothly introduced to the compound (c) at a methine carbon atom such as a cyclic methine carbon atom of the bridged cyclic hydrocarbon to provide a nitro compound or a carboxy compound of the bridged cyclic hydrocarbonwithhighconversionandselectivity. Contact of, for example, adamantane among the bridged cyclic hydrocarbons with the nitrogen oxide in the presence of the catalyst provides 1-nitroadamantane and/or 1,3-dinitroadamantane and/or 1,3,5-trinitroadamantane etc. Contact of adamantane with carbon monoxide and oxygen provides 1-carboxyadamantane and/or 1,3-dicarboxyadamantane and/or 1,3,5-tricarboxyadamantane etc. Moreover, contact of adamantane with the nitrogen oxide, carbon monoxide and oxygen in the presence of the catalyst provides 1-carboxy-3-nitroadamantane, 1-carboxy-3,5-dinitroadamantane, 1,3-dicarboxy-5-nitroadamantane etc. Furthermore, contact of 1-methyladamantane with the nitrogen oxide provides 1-methyl-3-nitroadamantane, contact of 1-methyladamantane with carbon monoxide and oxygen provides 1-carboxy-3-methyladamantane etc.
In (d) the compound having a methyl group or a methylene group at an adjacent site of an aromatic ring, a nitro group or a carboxyl group can be smoothly introduced thereto at the benzyl position. Contact of, for example, toluene among the compound having a methyl group or a methylene group at the benzyl position with the nitrogen oxide in the presence of the catalyst provides nitrobenzene etc. and contact of toluene with the carbon monoxide and oxygen provides phenylacetate. Use of ethylbenzene as a substrate provides 1-nitroethylbenzene, 1-phenylpropionate etc. Application of the process of the present invention to fluorene provides 9-carboxyfluorene.
The amount of the imide compound shown by the formula (1) may be selected within a broad range, for example, of about 0.0001 mole (0.01 mole %) to 1 mole (100 mole %), preferably about 0.001 mole (0.1 mole %) to 0.5 mole (50 mole %), more preferably about 0.01 to 0.30 mole, and may be practically about 0.01 to 0.25 mole, relative to 1 mole of the substrate.
The amount of the co-catalyst may be selected within a broad range of, for example, about 0.0001 mole (0.01 mole %) to 0.7 mole (70 mole %), preferably about 0.0001 mole to 0.5 mole, more preferably about 0.001 to 0.3 mole, andmaybe practically about 0.0005 to 0.1 mole (e.g., about 0.005 to 0.1 mole), relative to 1 mole of the substrate.
The ratio of the co-catalyst to the imide compound shown by the formula (1) may be selected within the range not interfering with the reaction rate or selectivity, for example, of about 0.001 to 10 mole of the co-catalyst, preferably about 0.005 to 5 mole, more preferably about 0.01 to 3 mole, andmay be practically about 0.01 to 5 mole, relative to 1 mole of the imide compound.
The amount of the nitrogen oxide may be selected depending upon the introduced amount of nitro group, within the range of, for example, about 1 mole or more (e.g., about 1 to 50 mole), preferably about 1.5 to 30 mole, and may be usually about 2 to 25 mole, relative to 1 mole of the substrate.
The amount of carbon monoxide may be selected within the range of, for example, about 1 mole or more (e.g., about 1 to 1000 mole), preferably excess mole, for example, about 1.5 to 100 mole (e.g., about 2 to 50 mole), more preferably about 2 to 30 mole (e.g., about 5 to 25 mole), relative to 1 mole of the substrate.
The amount of oxygen may be selected within the range of about 0.5 mole or more (e.g., about 0.5 to 100 mole), preferably about 0.5 to 30 mole, more preferably about 0.5 to 25 mole, relative to 1 mole of the substrate.
In a continuous reaction, when excess amount of carbon monoxide and oxygen are used, they can be used to supply to the reaction system continuously by, for example, circulating them.
The ratio of carbon monoxide (CO) to oxygen (O2) may be selected within the wide range, as far as the amount of the each component is within the above range, for example, of CO/O2=about 1/99 to 99.99/0.01 (mole %) [e.g., about 70/30 to 99/1 (mole %)]. Use of more amount of the carbon monoxide than that of oxygen is advantageous. The ratio of CO to O2 may be usually selected within the range of CO/O2=about 1/99 to 99/1 (mole %) [e.g., about 10/90 to 99/1 (mole %)], and may be preferably about 30/70 to 98/2 (mole %), more preferably about 50/50 to 95/5 (mole %), particularly about 60/40 to 90/10 (mole %).
The volume ratio of carbon monoxide to oxygen in a supply line may be selected within the range of, for example, CO/O2=about 1/99 to 99.99/0.01 (volume %) [e.g., about 70/30 to 99/1 (volume %)], and may be usually about 1/99 to 99/1 (volume %), preferably about 30/70 to 98/2 (volume %), more preferably about 50/50 to 95/5 (volume %), specifically about 60/40 to 90/10.
The nitration reaction and/or the carboxylation reaction can be conducted in the presence or absence of a solvent. As the solvent, use can be made of a solvent inert to reaction, examples of which are organic acids (e.g., carboxylic acids such as acetic acid and propionic acid), nitriles (e.g., acetonitrile, propionitrile, benzonitrile), amides (e.g., formamide, dimethylformamide), alcohols (e.g., ethanol, propanol, butanol, t-butanol, t-amylalcohol), aliphatic hydrocarbons (e.g., hexane, octane), aromatic hydrocarbons (e.g., benzene), organic halogen compounds (e.g., halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane, dichlorobenzene, and trifluoromethylbenzene; halogen-substituted carboxylic acids such as chloroacetic acid and trifluoroacetic acid; halogen-substituted acid anhydrides such as chloroacetic anhydride; halogen-substituted esters such as methyl chloroacetate and ethyl chloroacetate), nitro compounds (e.g., nitromethane, nitrobenzene), esters (e.g., ethyl acetate), ethers (e.g., dimethyl ether), and mixed solvents of these. Among them, carboxylic acids (e.g., acetic acid, propionic acid), organic halogen compounds and nitrites are preferred as the solvent. A mixture of two or more solvents serves to enhance the yield and selectivity. As the solvent mixtures, there may be mentioned a mixed solvent comprising at least one solvent selected from nitriles and organic halogen compounds (e.g., amixed solvent of a nitrile and an organic halogen compound, a mixed solvent of a nitrile and an organic acid), and the like. When the solvents are used in combination, the ratio for blending these solvents can be selected from a wide range. For instance, the ratio of a dominant primary solvent relative to the other solvent(s) ranges from about 1/99 to 99/1 (the former/the latter, by weight), preferably from about 5/95 to 95/5 (by weight), and more preferably about 10/90 to 90/10 (by weight) (e.g., 15/85 to 85/15 (by weight)).
In the present invention, the reactions can be smoothly conducted even in a comparatively mild or moderate condition. The reaction temperature may be suitably selected according to species of the reactions, species of the imide compounds or the substrates. For example, in the nitration reaction, the reaction temperature may be selected within the range of about 0 to 150xc2x0 C., preferably about 25 to 125xc2x0 C., more preferably about 30 to 100xc2x0 C. The nitration reaction smoothly proceeds at a comparatively lower temperature such as within the range about 20 to 60xc2x0 C. In the carboxylation reaction, the reaction temperature may be selected within the range of about 0 to 200xc2x0 C., preferably about 10 to 150xc2x0 C. (e.g., about 10 to 120xc2x0 C.), more preferably about 10 to 100xc2x0 C. (e.g., about 10 to 80xc2x0 C.). The reaction can be conducted under ambient pressure or in a pressure (under load).
When a nitrogen oxide is used as a reactant, a reaction in the presence of oxygen sometimes provides a nitroalcohol or an alcohol. The nitroalcohol is included in the nitro compound of the present invention.
The process of the present invention is useful for nitrating and/or carboxylating a substrate to provide a nitro compound and/or carboxyl compound corresponding to the substrate, efficiently. In the process, the compound can be obtained with high conversion and selectivity even in a mild and moderate condition. To be specific, when a mixture of carbon monoxide and oxygen is employed as a reactant a carboxyl group can be directly introduced to a substrate, and a carboxyl compound having more carbon atoms than the substrate depending on the introduced amount of carboxyl groups. Thus, in the present invention, a substrate is contacted with carbon monoxide and oxygen in the presence of the catalyst to provide a carboxyl compound at fewer reaction steps.
The reaction may be conducted in any of a batch, semi-batch, or continuous system. After the completion of the reaction, the reaction product can be easily separated and purified by a conventional separation/purification method including such separation methods as filtration, concentration, distillation, extraction, crystallisation, recrystallisation, adsorption, column chromatography, and a combination of these separation methods.
In the adamantane derivative shown by the formulas (2) and (3), a protective group of a hydroxymethyl group (the moiety corresponding to hydroxyl group of hydroxymethyl group) is included, for instance, t-butyl group, a cycloalkyl group (e.g., cyclohexyl group), an aryl. group (e.g., 2,4-dinitrophenyl group), an aralkyl group (e.g., benzyl group, 2,6-dichlorobenzyl group, 3-bromobenzyl group, 2-nitrobenzyl group, 4-dimethylcarbamoylbenzyl group, a benzyl group which may have a substituent such as triphenylmethyl group), tetrahydropyranyl group, an acyl group [e.g., a suturated aliphatic acyl group [(e.g., a saturated C2-6 aliphatic acyl group such as acetyl group, propionyl group, isopropionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pyvaloyl group, preferably a C2-4 saturated aliphatic acyl group), an aromatic acyl group (e.g., a C7-13 aromatic acyl group such as benzoyl group, p-phenylbenzoyl, phthaloyl, naphtoyl), an alicyclic acyl group (a cycloalkyl-carbonyl group; such as cyclohexylcarbonyl)], an alkoxy carbonyl group such as a C1-6alkoxy-carbonyl group (e.g., methoxy carbonyl group, ethoxy carbonyl group, propyloxy carbonyl group, isopropyloxy carbonyl group, isobutyloxy carbonyl group, t-butyloxy carbonyl group), an alalkyloxy carbonyl group (e.g., benzyloxy carbonyl group, methoxybenzyloxy carbonyl group), a carbamoyl group, which may have a substituent such as a C1-6alkyl group and a C6-14aryl group, (e.g., carbamoyl group, methylcarbamoyl group, ethylcarbamoyl group, phenyl carbamoyl group), a dialkylphosphinotioyl group (e.g., dimethylphosphinotioyl group), a diarylphosphinotioyl group (e.g., diophenylphosphinotioyl group). A preferred protective group of hydroxymethyl group includes, for instance, an acyl group (specifically, a saturated C2-6aliphatic acyl group etc., more specifically, a saturated C2-4aliphatic acyl group etc.), a C1-6alkoxy-carbonyl group, a carbamoyl group which may have a substituent.
A protective group of amino group includes, for example, as illustrated in the paragraph of the protective group of the hydroxyl group, t-butyl group, an aralkyl group, a non-polymezable acyl group [such as a saturated aliphatic acyl group (e.g., a saturated C2-6aliphatic acyl group, especially, a saturated C2-4aliphatic acyl group), an aromatic acyl group (e.g., a C7-13aromatic acyl group), an alicyclic acyl group], an alkoxy carbonyl group (e.g., a C1-6alkoxy carbonyl group), an aralkyloxy carbonyl group, a dialkylphosphinotioyl group, a diarylphosphinotioyl group. A preferred protective group of amino group comprises, for instance, a non-polymerizable acyl group [such as a saturated C2-6aliphatic acyl group (specifically, a saturated C2-4aliphatic acyl group), a C7-13aromatic acyl group], an alkoxy carbonyl group (specifically, a C1-6alkoxy carbonyl group).
An N-substituted amino group includes, for example, a mono- or di-C1-6alkylamino group (e.g., methylamino group, ethylamino group, a propylamino group, dimethylamino group, diethylamino group), prefferably, a mono- or di-C1-4alkylamino group.
A protective group of a carboxyl group comprises, for instance, an alkoxy group such as a C1-10alkoxy group (e.g., methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, s-butoxy group, t-butoxy group, hexyloxy group), preferably, a C1-6alkoxy group, especially, a C1-4alkoxy group, a cycloalkyloxy group (e.g., cyclohexyloxy group), an aryloxy group (e.g., phenoxy group), an aralkyloxy group (e.g., benzyloxy group, diphenylmethyloxy group), a trialkylsilyloxy group (e.g., trimethylsilyloxy group), an amino group which may have a substituent [amino group; an N-substituted amino group, such as a mono- or di-C1-6alkyl amino group (e. g., methylamino group, dimethylamino group, ethylamino group, diethylamino group)], hydrazino group, an alkoxy carbonyl hydrazino group (e.g., t-butoxycarbonylhydrazino group), an aralkyloxycarbonylhydrazino group (e.g., benzyloxycarbonylhydrazino group). A preferred protective group of carboxyl group includes an alkoxy group (especially, a C1-6alkoxy group), an amino group which may have a substituent (e.g., an N-substituted amino group, especially, a mono- or di-C1-6alkylamino group).
An alkyl group comprises, for instance, a C1-6alkyl group, such as methyl, ethyl, propyl, isopropyl, butyl, isoutyl, s-butyl, t-butyl, hexyl, preferrably, a C1-4alkyl group, more preferably, methyl group or ethyl group.
In the compound shown by the formula (3), a substituent of a carbamoyl group includes, for example, a C1-6alkyl group such as methyl, ethyl, propyl, butyl, and isobutyl group and a C6-14aryl group such as phenyl and naphthyl group. A substituted hydrooxycarbonylamino group includes, for example, a C1-6alkoxy-carbonylamino group such as methoxycarbonylamino, ethoxycarbonylamino, propoxycarbonylamino, and butoxycarbonylamino group; a C6-14aryloxy-carbonylamino group such as phenyloxycarbonylamino and naphtyloxycarbonylamino group; and a C7-15aralkyloxy-carbonylamino group such as benzyloxycarbonylamino group.
Examples of a saturated aliphatic acylamino group include a saturated C2-6aliphatic acylamino group such as acetylamino, propionylamino, isopropionylamino, butylylamino, isobutylylamino, valerylamino, isovalerylamino, and pivaloylamino group, and preferably a saturated C2-4aliphatic acylamino group. An aromatic acylamino group includes, for example, an aromatic C7-13acylamino such as benzoylamino and naphtoylamino group. A substituted oxycarbonyl group includes, for example, a C1-6alkoxy-carbonyl group such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl and butoxycarbonyl group; a C6-14aryloxy-carbonyl group such as phenyloxycarbonyl and naphtyloxycarbonyl group; a C7-15aralkyloxy-carbonyl group such as benzyloxycarbonyl group. An alkyl group as a substituent of an amino group includes, for example, a C1-6alkyl group such as methyl, ethyl, propyl, butyl and isobutyl group.
Examples of a preferred X1 include nitro group, amino group, a C2-6acylamino group corresponding to an amino group protected by a C2-6acyl group, a C1-6alkoxycarbonylamino group corresponding to an amino group protected by a C1-6alkoxy-carbonyl group, carboxyl group, a C1-10-alkoxy-carbonyl group corresponding to a carboxyl group protected by a C1-10loalkoxy group (especially, a C1-6alkoxy-carbonyl group), a carbamoyl group, which may have a substituent, corresponding to a carboxyl group protected by an amino group which may have a substituent, hydroxymethyl group, isocyanato group. Examples of a preferred X2 include amino group, a C2-6acylamino group corresponding to an amino group protected by a C2-6acyl group, a C1-6alkoxy-carbonylamino group corresponding to an amino group protected by a C1-6alkoxy-carbonyl group, hydroxymethyl group, isocyanato group, depending on species of X1.
Examples of a preferred X3 or X4 include hydrogen atom, an alkyl group, nitro. group, amino group, a C2-6acylamino group, a C1-6alkoxy-carbonylamino group, carboxyl group, a C1-10loalkoxy-carbonyl group (particularly a C1-6alkoxy-carbonyl group), a carbamoyl group which may have a substituent, hydroxymethyl group and isocyanato group.
A preferred X5 includes, for example, a carbamoyl group which may have a substituent, a C1-6alkoxycarbonylamino group, a saturated aliphatic C2-6acylamino group and an aromatic C7-13acylamino group. A preferred X6 includes, for example, carboxyl group, a C1-10-alkoxycarbonyl group, amino group, a C2-6acylamino group, a C1-6alkoxy-carbonylamino group and nitro group, depending on species of X5.
A preferred X7 or X8 includes, for example, a substituent exemplified as the preferred X3 or X4.
When such novel adamantane derivatives have an acidic group or a basic group, they may form salts.
Among the compounds ""shown by the formula (2), as a nitro group-containing adamantane derivative, there may be exemplified 1-amino-3-nitroadamantane, 1-amino-3-methyl-5-nitroadamantane, 1-amino-3,5-dimethyl-7-nitroadamantane, 1-amino-3,5-dinitroadamantane, 1-methoxycarbonylamino-3-nitroadamantane, 1,3-bis(methoxycarbonylamino)-5-nitroadamnatane, 1-methoxycarbonylamino-3,5-dinitroadamantane, 1-ethoxycarbonylamino-3-nitroadamantane, 1-acetylamino-3-nitroadamantane, 1-acetylamino-3,5-dinitroadamantane, 1,3-bis(acetylamino)-5-nitroadamantane, 1-hydroxymethyl-3-nitroadamantane and 1-isocyanato-3-nitroadamantane.
As an adamantane derivative having an amino group or N-substituted amino group which may be protected by a protecting group, there may be mentioned, for example, 1-amino-3-isocyanatoadamantane, 1-amino-3-isocyanato-5-methyladamantane, 1-isocyanato-3-methoxycarbonylaminoadamantane, 1-isocyanato-3-(N-methylamino)adamantane and 1-acetylamino-3-isocyanatoadamantane.
Examples of an adamantane derivative having a carboxyl group which may be protected by a protecting group include 1-carboxy-3-hydroxymethyladamantane, 1,3-dicarboxy-5-hydroxymethyladamantane, 1-carboxy-3,5-bis(hydroxymethyl)adamantane, 1-carboxy-3-hydroxymethyl-5-methyladamantane, 1-hydroxymethyl-3-methoxycarbonyladamantane, 1-ethoxycarbonyl-3-hydroxymethyladamantane, 1-hydroxymethyl-3-(N,N-dimethylcarbamoyl)adamantane, 1-isocyanato-3-methoxycarbonyladamantane and 1-isocyanato-3-(N,N-dimethylcarbamoyl)adamantane.
An adamantane derivative having a hydroxymethyl group which may be protected by a protecting group includes, for example, 1-acetyloxymethyl-3-isocyanatoadamantane and 1-propionyloxymethyl-3-isocyanatoadamantane.
Among the adamantane derivatives shown by the formula (3), an adamantane derivative having a carbamoyl group which may have a substituent includes, for example, 1-carboxy-3-(N-methylcarbamoyl)adamantane, 1-carboxy-3-(N,N-dimethylcarbamoyl)adamantane, 1-carboxy-3-methyl-5-(N,N-dimethylcarbamoyl)adamantane, 1-methoxycarbonyl-3-(N,N-dimethylcarbamoyl)adamantane, 1-amino-3-(N,N-dimethylcarbamoyl)adamantane, 1-acetylamino-3-(N,N-dimethylcarbamoyl)adamantane, 1-methoxycarbonylamino-3-(N,N-dimethylcarbamoyl)adamantane and 1-(N,N-dimethylcarbamoyl)-3-nitroadamantane.
Examples of a nitro group-containing adamantane derivative include 1-methoxycarbonyl-3-nitroadamantane, 1,3-bis(methoxycarbonyl)-5-nitroadamantane, 1-methoxycarbonyl-3,5-dinitroadamantane, 1-methoxycarbonyl-3-methyl-5-nitroadamantane, 1-ethoxycarbonyl-3-nitroadamantane, 1-nitro-3-propoxycarbonyladamantane and 1-nitro-3-phenoxycarbonyladamantane.
A substituted hydroxycarbonylamino group-containing adamantane derivative includes, for example, 1-methoxycarbonyl-3-methoxycarbonylaminoadamantane, 1-methoxycarbonyl-3-methoxycarbonylamino-5-methyladamantane, 1-ethoxycarbonyl-3-ethoxycarbonylaminoadamantane, 1-hydroxymethyl-3-methoxycarbonylaminoadamantane, 1-amino-3-methoxycarbonylaminoadamantane, 1-amino-3-methoxycarbonylamino-5-methyladamantane, 1-acethylamino-3-methoxycarbonylaminoadamantane and 1-acetylamino-3-ethoxycarbonylaminoadamantane.
A saturated aliphatic or aromatic amino group-containing adamantane derivative includes, for example, 1-acetylamino-3-carboxyadamantane, 1,3-bis(acetylamino)-5-carboxyadamantane, 1-acetylamino-3,5-dicarboxyadamantane, 1-acetylamino-3-carboxy-5-methyladamantane, 1-benzoylamino-3-carboxyadamantane, 1-acetylamino-3-hydroxymethyladamantane, 1-acetylamino-3-aminoadamantane, 1,3-bis(acetylamino)-5-aminoadamantane, 1-acetylamino-3,5-diaminoadamantane, 1-acetylamino-3-(N,N-dimethylamino)adamantane and 1-acetylamino-3-(N-methylamino)adamantane.
The adamantane derivative shown by the formula (2) or (3) may have other substituents, for example, a halogen atom, an oxo group, a hydroxyalkyl group (e.g., hydroxy C2-4alkyl groups such as 2-hydroxyethyl group), an acyl group (e.g., C1-6acyl groups such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl and pivaloyl group), an alkoxycarbonyl group (e.g., C1-6alkoxy-carbonyl group such as methoxycarbonyl, ethoxy-carbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, t-butoxycarbonyl and hexyloxycarbonyl group) and cyano group.
The adamantane derivatives shown by the formulas (2) and (3) and an adamantane derivative having at least two substituents selected from the group consisting of a nitro group, an amino group or N-substituted amino group which may be protected by a protecting group, a carboxyl group which may be protected by a protecting group, a hydroxymethyl group which may be protected by a protecting group, and an isocyanato group, at a methine carbon atom of a bridgehead position of adanantane skelton can be obtained by the foll owing reaction step scheme (I) or (II), or by combinating the reaction step scheme (I) and (II). 
wherein X1b represents a nitro group; X1c represents an amino group; X1d represents an isocyanato group; X2a, X2b, X2c and X2d represent a hydrogen atom, a nitro group, an amino or N-substituted amino group which may be protected by a protecting group, a carboxyl group which may be protected by a protecting group, a hydroxymethyl group which may be protected by a protecting group, or an isocyanato group respectively; and X3 and X4 respectively have the same meanings as defined above). 
wherein X1f represents a carboxyl group; X1g represents a hydroxymethyl group; X2e, X2f and X2g represents a hydrogen atom, a nitro group, an amino or N-substituted amino group which may be protected by a protecting group, a carboxyl group which may be protected by a protecting group, a hydroxymethyl group which may be protected by a protecting group, or an isocyanato group; and X3 and X4 each has the same meanings as defined above.)
The nitration (nitration reaction which derives compound (2b) from compound (2a)) of the step (I-1) in the reaction step scheme (I) may be carried out by the nitration method, i.e., the method of contacting a substrate with a nitrogen oxide at least, in the presence of the imide compound shown by the formula (1). A nitro group can be introduced to a methine carbon atom of a bridgehead position by the nitration. When X2a in the compound (2a) is hydrogen atom, X2a may be also converted into a nitro group according to reaction conditions. For example, nitration of an adamantane may give 1-nitroadamantane and/or 1,3-dinitroadamantane. Further, the nitration of 1-nitroadamantane, 1-carboxyadamantane and 1-hydroxyadamantane may give 1,3-dinitroadamantane, 1-carboxy-3-nitroadamantane and 1-hydroxy-3-nitroadamantane, respectively.
The reduction (reductive reaction which derives compound (2c) from compound (2b)) of the step (I-2) may be carried out by a conventional method such as catalytic hydrogenation process using hydrogen as a reducing agent and reduction process using a hydrogenation reducing agent.
In the catalytic hydrogenation, a simple substance of a metal such as platinum, palladium, nickel, cobalt, iron and copper, a compound containing such metal elements (e.g., platinum oxide, palladium black, palladium carbon and copper chromite) or the like may be used as a catalyst. The amount of the catalyst is practically about 0.02 to 1 mole relative to 1 mole of a substrate. Further, in a catalytic hydrogenation, the reaction temperature may be, for example, about xe2x88x9220 to 100xc2x0 C. (e.g., about 0 to 90xc2x0 C.). A hydrogen pressure is practically about 1 to 100 atm (e.g., about 1 to 50 atm).
In the reducing process using a hydrogenation reducing agent, the hydrogenation reducing agent to be used includes, for example, aluminium hydride, lithium aluminium hydride, lithium trialkoxyaluminium hydride, sodium boron hydride, diborane, bis-3-methyl-2-butylborane, ametal (e.g., zinc, tin, iron) acid, a sulfide and hydrazine. The reducing process using a hydrogenation reducing agent may be conducted also in the presence of a Lewis acid such as aluminium chloride anhydride and boron trifluoride. The amount of the hydrogenation reducing agent is usually about 1 mole or more (e.g., about 1 to 10 mole) relative to 1 mole of a substrate. In the reducing process using the hydrogenation reducing agent, a reaction temperature is practically about 0 to 200xc2x0 C. (e.g., about 0 to 170xc2x0 C.).
Incidentally, the reduction reaction (the catalytic hydrogenation and the process using the hydrogenation reducing agent) may be carried out in the presence of a solvent inert to the reduction reaction (e.g., an alcohol such as methanol and further a solvent exemplified in the nitration reaction such as a carboxylic acid, an ether, an ester and an amide). Moreover, when reduction reaction is conducted by the catalytic hydrogenation, an acid such as hydrochloric acid may be added to the reaction system in order to improve the catalytic activity.
The nitro group X1b of the compound (2b) is converted into an amino group by the reduction reaction. In the compound (2b), when X2b is a nitro group, the nitro group may be also converted into an amino group according to reaction conditions. For example, the reduction of 1-nitroadamantane may give 1-aminoadamantane, and the reduction of 1,3-dinitroadamantane may give 1-amino-3-nitroadamantane and/or 1,3-diaminoadamantane. Further, the each reduction of 1-carboxy-3-nitroadamantane and 1-hydroxymethyl-3-nitroadamantane may give 1-amino-3-carboxyadamantane and 1-amino-3-hydroxymethyladamantane respectively.
The isocyanation (reaction deriving compound (2d) from compound (2c)) of the step (I-3) may be carried out by a conventional method, for example, the method using phosgene. The reaction of the compound (2c) with phosgene may be conducted, for example, in the presence or absence of a solvent at a temperature of about xe2x88x9210 to 100xc2x0 C. The amount of phosgene is, for example, about 0.8 to 10 mole and preferably about 1 to 2 mole relative to 1 mole of the compound (2c).
The amino group X1c of the compound (2c) may be converted into an isocyanato group by the reaction mentioned above. When X2c of the compound (2c) is an amino group, the amino group may be converted into an isocyanato group according to conditions. For example, the isocyanation of 1-aminoadamantane may give 1-isocyanatoadamantane. Further, each of 1-amino-3-nitroadamantane, 1.3-diaminoadamantane, 1-amino-3-carboxyadamantane and 1-amino-3-hydroxymethyladamantane may be subjected to isocyanation to give 1-isocyanato-3-nitroadamantane, 1,3-diisocynatoadamantane, 1-isocyanato-3-carboxyadamantane and 1-isocyanato-3-hydroxymethyladamantane respectively.
The carboxylation (reaction deriving compound (2f) from compound (2e)) of the step (II-1) in the reaction step scheme (II) may be carried out by the above-mentioned carboxylation, i.e., the process for contacting a substrate with at least carbon dioxide and oxygen in the presence of the imide compound shown by the formula (1). A carboxyl group can be introduced to a methine carbon atom at a bridgehead position of the compound (2e) by the carboxylation. When X2e of the compound (2e) is a hydrogen atom, X2e may be also converted to a carboxyl group according to reaction conditions. For example, an adamantane may be carboxylated to produce 1-carboxyadamantane and/or 1,3-dicarboxyadamantane as previously described. Further, the carboxylation of each 1-carboxyadamantane and 1-nitroadamantane may give 1,3-dicarboxyadamantane and 1-carboxy-3-nitroadamantane respectively.
The reduction (reaction introducing compound (2g) from compound (2f)) of the step (II-2) may be carried out by a conventional method such as catalytic hydrogenation using hydrogen as a reducing agent and a method using a hydrogenation reducing agent described for the step (I-2). In this step, a preferred hydrogenation reducing agent includes, for example, a sodium boron hydride-Lewis acid, aluminum hydride, lithium aluminum hydride, lithium trialkoxyaluminum hydride and diborane.
The reduction reaction may convert the carboxyl group X1f of the compound (2f) may be converted to a hydroxymethyl group. Moreover, when X2f of the compound (2f) is a carboxyl group, the carboxyl group may be also converted to a hydroxymethyl group according to reaction conditions. For example, the reduction of 1-carboxyadamantane gives 1-hydroxymethyladamantane, and the reduction of 1,3-dicarboxyadamantane gives 1-carboxy-3-hydroxymethyladamantane and/or 1,3-bis(hydroxymethyl)adamantane.
Incidentally, according to the species of substrates, a hydroxylmethyl group (a site corresponding to a hydroxyl group of the hydroxymethyl group), an amino group and a carboxyl group of the reaction component or the reaction product may be protected by the above protecting group before, after, or during the each step. The introduction and elimination of the protecting group for a hydroxymethyl group, an amino group and a carboxyl group may be carried out by a conventional method such as esterification, amidation, carbamation, carbonation, hydrolysis and hydrogenolysis, if necessary, using an acid, an alkali, an ion-exchange resin, a catalyst for hydrogenolysis or the like.
When an acyl group is.used as a protecting group for a hydroxylmethyl group or an amino group (acyloxymethyl group or acylamino group is formed), the hydroxymethyl group or the amino group of the substrate may be protected by allowing to act an acylating agent on the substrate. Examples of the acylating agent include C2-6aliphatic monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, valeric acid and pivalic acid (preferably C2-4carboxylic acids), and reactive derivatives thereof [e.g., acid anhydrides such as acetic anhydride and valeic anhydride, acid halides such as acid chloride (e.g., acetyl chloride, propionyl chloride and butyryl chloride)]. When an acid anhydride or an acid halide is used as an acylating agent, the acylation reaction is usually carried out in the presence of a base in order to capture the acid which is a by-product in the reaction. As the base, there may be exemplified an inorganic base (e.g., a hydroxide of an alkai metal such as sodium hydroxide; a hydroxide of alkaline earth metal such as barium hydroxide; carbonate of an alkaline metal such as sodium carbonate; a carbonate of an alkaline earth metal such as barium carbonate; a hydrogencarbonate of an alkaline metal such as sodium hydrogencarbonate); and an organic base (e.g., a tertiary amine such as triethylamine and N-methylpiperidine; a basic heterocyclic compound containing a nitrogen atom such as pyridine; an alkoxide of an alkali metal such as sodium methoxide and sodium ethoxide). The acylating agent may be used singly or in combination of two or more.
For example, 1-acetylamino-3-nitroadamantane can be obtained by acting acethyl chloride on 1-amino-3-nitroadamantane in the presence of the base.
When a substituted hydroxycarbonyl group is used as a protecting group for a hydroxymethyl group or an amino group, the hydroxyl group or the amino group may be protected by reacting a substrate with a halocarbonate to obtain a compound having a carbonate group or carbamate group. The reaction may be usually carried out in the presence of a base. As the base, the similar base to one exemplified above may be used.
When a carbamoyl group is used as a protecting group for a hydroxymethyl group, the hydroxymethyl group may be protected, for example, by reacting a substrate with an isocyanate compound, if necessary, in the presence of the base exemplified above to obtain a compound having a carbamoyloxy group.
Moreover, an adamantane derivative having N-substituted amino group may be produced, for example, by reacting a substrate with a hydrocarbon halide (e.g., aliphatic hydrocarbon halide such as iodomethane, iodoethane, iodobutane, bromomethane, bromoethane, bromobutane, chloromethane and chloroethane). The reaction may be conducted in the presence of a de-hydrogen halide agent (an agent for eliminating a hydrogen halide). As the de-hydrogen halide agent, a base, for example, the above exemplified may be practically used. The reaction may be conducted in solvent inert to the reaction. As such solvent, use may be made of exemplified solvents for the nitration reaction such as a hydrocarbon halide, an ether, an ester and an amide.
When a substituted hydroxyl group (e.g., an alkoxy group) protects a carboxyl group [(i.e., when a substituted hydroxycarbonyl group (an ester group)] is formed), the carboxyl group may be protected by reacting a carboxyl group-containing compound or derivative thereof (e.g., an acid halid such as an acid chloride) with an alcohol (e.g., methanol, ethanol) or reactive derivative thereof (e.g., lower alkyl ester), if necessary, in the presence of an acid (e.g., a mineral acid such as hydrochloric acid and sulfuric acid) or an base (e.g., the base exemplified above) to produce a compound having the corresponding ester group. The lower alkyl ester inclu des, for example, acetic acid-C1-4alkyl ester such as methyl acetate and ethyl acetate or the corresponding propionate (e.g., methyl propionate, ethyl propionate). For example, 1-methoxycarbonyl-3-nitroadamantane may be obtained by reacting 1-carboxy-3-nitroadamantane with methanol in the presence of an acid, or by acting thionyl chloride on 1-carboxy-3-nitroadamantane followed by reacting with methanol in the presence of a base.
Moreover, when a carboxyl group is converted into a group having an amide bond with use of an amino group as a protecting group for the carboxyl group (i.e., when an N-substituted or unsubstituted carbamoyl group is formed), a condition of a conventional process for forming an amido bond may be applied. The process for forming an amido bond may be carried out, for example, by following methods:
(a) a method by a mixed acid anhydride, i.e., a method which comprises reacting a compound having a carboxyl group with an acid halide (e.g., acetyl chloride, propionyl chloride, acetyl bromide) to produce a mixed acid anhydride followed by reacting the given mixed acid anhydride with an amine compound;
(b) a method by an active ester, i.e., a method which comprises converting a substrate into an active ester thereof, such as p-nitrophenylester, an ester with N-hydroxysuccinimide, an ester with 1-hydroxybenzotriazol or the like followed by reacting the given ester with an amine compound;
(c) a method by a carbodiimide, i.e., a method which condenses an amine compound with a substrate in the presence of an activating agent such as dicyclohexylcarbodiimide and carbonyldlimidazol; or
(d) a method which comprises converting a substrate into a carboxylic anhydride thereof by a dehydrator such as acetic anhydride followed by reacting the given carboxylic anhydride with an amine compound, or a method which comprises converting a substrate to an acid halide thereof followed by reacting the acid halide with an amine compound.
The amine compound used in the amide bond forming reaction includes, for example, ammonia or a derivative thereof (e.g., ammonium halide such as ammonium chloride), a primary amine, a secondary amine, hydrazine or a derivative thereof (e.g., alkoxycarbonylhydrazine such as t-butoxycarbonylhydrazine, alkoxycarbonylhydrazine such as benzyloxycarbonylhydrazine).
For example, the reaction of an acid halide with an amine compound may be carried out in a suitable solvent, in the presence of an basic compound. As the basic compound, use may be made of a basic compound exemplified for the reaction of the compound (Ia) having an amino group or the compound (1d) with a hydrocarbon halide and the like.
Moreover, as the solvent, an organic solvent (e.g., an ether, an ester, an amide) exemplified for the nitration reaction may be employed.
Furthermore, the compound having a carbamoyl group may be obtained by reacting a compound having an ester group (e.g., an alkoxycarbonyl group, an aryloxycarbonyl group, an aralkyloxycarbonyl group) as a protected carboxyl group with the amine compound in the presence of a catalyst comprising a metal compound.
Examples of the metal compound used in the reaction (the amidation reaction) include a conventional catalyst for transesterification (including a catalyst for transferring an ester to an amide), for example, a transition metal compound such as a compound comprising Group 3B element of the Periodic Table of Elements (e.g., aluminum compound such as AlCl3), a compound comprising Group 4A element of the Periodic Table of Elements (e.g., titanium compound such as TiCl4), a compound comprising Group 3A element (e.g., samarium compound such as SmI2) of the Periodic Table of Elements.
The amount of the catalyst may be liberally selected within a broad range, for example, about 0.1 mole % to 1 equivalent, preferably about 0.5 to 50 mole %, and more preferably about 1 to 25 mole % (e.g., about 5 to 20 mole %) relative to a compound having an ester group.
The ratio of the amine compound to the ester group-containing compound is, for example, about 0.5 to 5 mole, preferably about 0.8 mole or more (e.g., about 0.8 to 5 mole), and specifically about 1 mole or more (e.g., about 1 to 3 mole, in particular about 1 to 1.5 mole) of ammonia or the like relative to 1 equivalent of the ester group-containing compound.
The amidation reaction may be carried out in the presence or absence of a solvent inert to the reaction. As the reaction solvent, there may be exemplified an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, a ketone, an ether, a non-protonic polar solvent and a mixture thereof. The reaction temperature may be selected within the range of, for example, about 0 to 150xc2x0 C., and preferably about 25 to 120xc2x0 C.
The adamantane derivative shown by the formula (2) and (3) of the present invention can be concretely produced as follows.
For example, among compounds shown by the formula (2), a compound having a nitro group and an amino group which may have a protecting group or a substituent can be produced through the steps (I-1) and (I-2). A compound having a nitro group and an isocyanato group can be produced through the steps (I-1), (I-2) and (I-3). A compound having a nitro group and a hydroxymethyl group which may be protected by a protecting group may be obtained through the steps (I-1), (II-1) and (II-2).
A compound having an amino group which may have a protective group or a substituent, and an isocyanato group may be produced through the steps (I-1), (I-2) and (I-3).
A compound having a carboxyl group, which may be protected by protective group, and a hydroxymethyl group which may be protected by a protecting group may be obtained, for example, through the step (II-1) and (II-2). A compound having a carboxyl group which may be protected by a protecting group, and an isocyanato group may be obtained through the steps (I-1), (I-2), (I-3) and (II-1).
A compound having a hydroxylmethyl group which may be protected by a protecting group, and an isocyanato group may be produced through the steps (I-1), (I-2), (I-3), (II-1) and (II-2).
Among the compounds shown by the formula (3), a compound having a carbamoyl group which may have a substituent, and a carboxyl group may be obtained through the step (II-1) and the step of introducing an amino group to a carboxyl group (the amide group-forming step). A compound having a carbamoyl group which may have a substituent, and a substituted hydroxycarbonyl group may be obtained through the step (II-1), the step for introducing an amino group to a carboxyl group and the step for introducing a substituted hydroxyl group to another carboxyl group (the ester group-forming step). A compound having a carbamoyl group which may have a substituent, and an amino group which may have a protecting group or a substituent may be obtained through the steps (I-1), (I-2), (II-1) and the step of introducing an amino group to the carboxyl group. A compound having a carbamoyl group which may have a substituent, and a nitro group may be obtained through the steps (I-1), (II-1) and the step of introducing an amino group to the carboxyl group.
A compound having a nitro group and a substituted hydroxycarbonyl group may be produced through the steps (I-1), (II-1), and the step of introducing a substituted hydroxyl group to the carboxyl group. A compound having a substituted hydroxycarbonylamino group and a substituted hydroxycarbonyl group may be obtained through the steps (I-1), (I-2), (II-1) and the step of introducing the substituted hydroxycarbonyl group to an amino group (the carbamate group-forming step) and the step of introducing a substituted hydroxyl group to the carboxy group. A compound having a substituted hydroxycarbonylamino group and, a hydroxyl group may be protected by a protecting group through the steps (I-1), (I-2), (II-1), (II-2), and the step of introducing an amino group to the substituted hydroxycarbonyl group. A compound having a substituted hydroxycarbonylamino group and an amino group which may be protected by a protecting group may be obtained through the steps (I-1), (I-2), (I-3), and the step of introducing an substituted hydroxycarbonyl group to the amino group. A compound having a saturated aliphatic or aromatic acylamino group and a carboxylg roup may be obtained through the steps (I-1), (I-2), (II-1), and the step of introducing an acyl group to an amino group. A compound having a saturated aliphatic or aromatic acylamino group and a hydroxylmethyl group which may be protected by a protecting groupmaybeobtainedthroughthesteps (I-1), (I-2), (II-1), (II-2), and the step of introducing an acyl group to an amino group. A compound having a saturated aliphatic or aromatic acylamino group and an amino group which may be protected by an alkyl group may be obtained through the steps (I-1), (I-2), and the step of introducing an acyl group to an amino group. The introduction of an amino group or a substituted hydroxyl group to a carboxyl group, introduction of a substituted hydroxycarbonyl group to an amino group, and introduction of an acyl group to an amino group may be carried out by the above method for introducing a protecting group.
Further, the diaminoadamantane derivative (compound (2j)) having at least two groups of amino groups or N-substituted amino groups, which may be protected by a protecting group, at bridgehead position of adamantane skeleton may be obtained by nitrating the compound (compound (2h)) in which X2a of the compound (2a) is a hydrogen atom or a nitro group according to the step (I-1) to form a dinitro body (compound (2i)) in which X1b and X2b of the compound (2b) are nitro groups, and then reducing it according to the step (I-2) to convert into a diamino body in which X1c and X2c of the compound (2c) are an amino groups and, if necessary, introducing a protecting group or a substituent to the amino group. In the method, since the diamino body is directly formed in the form of not salt but free, the alternation or denaturation, decomposition or decrease of recover efficiency, each occuring when salt of a diamino body becomes free may be avoid. Therefore, the diamino adamantane derivative may be efficiently produced with high yield.
In the method of the present invention, a substrate may be directly nitrated and/or carboxylated efficiently even in a mild or moderate condition since an imide compound shown by the formula (1) is combined with at least one reacting agent selected from (i) a nitrogen oxide and (ii) a mixture of carbon monoxide and oxygen. Moreover, to a substrate, at least one functional group selected from a nitro group and a carboxyl group can be introduced to produce a nitro compound and/or carboxy compound with high conversion and selectivity even in the mild or moderate condition.
Moreover, nitrogen oxide, which causes environmental pollution, is efficiently utilized to form a nitro compound may be produced with high conversion and selectivity. Further, a carboxy compound having more carbon atoms than that of a substrate may be efficiently produced by a simple operation through fewer steps.
Further, in the present invention, a novel adamantane derivative useful for a high functional material may be provided. A diamino body of adamantane can be produced in high yield.